Dont buy proform roller rockers

I had a big block with a about 4000 miles on a fresh rebuild. I put some proform roller rocker on it and and they came apart. It comes to find out this is a common problem so i thought i would let evrybody know not to buy them. heres a pic of whats let of the #8 piston of my motor

wow..... what a bummer. They going to compensate you anyway for what has happened?

holy shite!!(kinda looks like what happens when "buddy"drops a carb linkage pin into intake and doesn't tell you (no pics-sorry!!!)......Ironically it was also on a 400 I built!(had less than 50 miles on it....)

haven't got ahold of them yet but i hope so

Any pic's of the cyl. head and the valve that hit the piston?:corn:

I was helping him tear this motor down this sunday and the carnage was impressive. It started as a quick motor swap but when he pulled the carb off and we saw piston pieces :eeek: We felt obligated to pull the heads and see what let go. :redneck: It goof things up real good to say the least.

how did a rocker take out a piston?? if it breaks the valve closes, right?= chunks in the head. how did chunks in the valve cover bust a piston. you mighta heard some clatter before the piston let go?? I dont get it??:booo:

CHOP SHOP said:

how did a rocker take out a piston?? if it breaks the valve closes, right?= chunks in the head. how did chunks in the valve cover bust a piston. you mighta heard some clatter before the piston let go?? I dont get it??:booo:

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I'm with you on this one......

CHOP SHOP said:

how did a rocker take out a piston?? if it breaks the valve closes, right?= chunks in the head. how did chunks in the valve cover bust a piston. you mighta heard some clatter before the piston let go?? I dont get it??:booo:

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I was kinda wondering the same thing. Maybe the broken rocker thrashing around broke a valve spring or knocked a keeper off, allowing the valve to drop???

It was a roller rocker and the pin came loose in the roller portion in a way that jammed the valve open. Picture the roller turning in the arm and making the arm "adjustment" tighter.

How did you see the piston when you took the carb off? Thats damn near impossible. :eeek:

IMO looks like someone doesn't know how to rebuild a motor and such person with such awsome skills is who you should be after, not said company.

Post up a pic of the head. I bet you threw a rod, and it slapped the **** out of the head.Thats typically what they look like. I have a nice 355 piston on my desk at work as a paper weight because of this

crazybluerider said:

It was a roller rocker and the pin came loose in the roller portion in a way that jammed the valve open. Picture the roller turning in the arm and making the arm "adjustment" tighter.

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You dont think that maybe the piston gave loose, hitting the bottom of the head with such force to knock the rocker loose????

JOOP said:

How did you see the piston when you took the carb off? Thats damn near impossible. :eeek:

IMO looks like someone doesn't know how to rebuild a motor and such person with such awsome skills is who you should be after, not said company.

Post up a pic of the head. I bet you threw a rod, and it slapped the **** out of the head.Thats typically what they look like. I have a nice 355 piston on my desk at work as a paper weight because of this

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Parts of the piston and half of a ring were in the intake.

You dont think that maybe the piston gave loose, hitting the bottom of the head with such force to knock the rocker loose????

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Could have. It was just an idea. Jimmy's builder says that he has had problems with these arms before. He is not the one who built the motor originally so I dont think he is covering his ass.

pro form will probably replace the broken rocker, as for the other parts you will prob. be on youre own. :booo:

Dont buy the rocker stud kits they have either. my friend fred has a 68 biscayne with a nothing more than mild 400 in it and he has snapped two of the studs this year so far.

I ran their cromolly pushrods and roller rockers in the 350 in my old toy and never had an issue. As far as I know its still going strong as it was the day I got rid of it.

CHOP SHOP said:

how did a rocker take out a piston?? if it breaks the valve closes, right?= chunks in the head. how did chunks in the valve cover bust a piston. you mighta heard some clatter before the piston let go?? I dont get it??:booo:

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There was alot of noise i was babying it home cause i didnt know for sure what it was and about 3 blocks from home it let go with a bang. The valve had to be open cause how else would you get chunks of rings and piston and oil in the intake right under the carb. I dont know who built the motor a friend of a friend had it built and i got it when i bought the truck. I talked to my motor builder (dg machine) and he that that is a common problem with them.

Were they aluminum? I have always been partial to the Crane/Comp Cam series of rockers.

Let me just say that your picture looks very familiar.:eeek:

In my case a rod bolt backed out, then the other bolt snapped under stress. The piston was in thousands of pieces, and yes bits were found in the intake.
I had several bent pushrods, and a cam that came out in five pieces, I can see how it would have been quite possible for a rocker to have broken as well.



I only saved 6 rods, and the crank out of that motor (long block).

It's only money......right?

here are some more pics of the damage